The present invention relates generally to apparatuses for generating spherical data sets. More specifically, the present invention relates to apparatuses employing both a relatively long lens and a spherical mirror. Corresponding methods for generating a spherical data set is also disclosed.
Devices employing spherical data sets for generating a viewable image are known. For example, U.S. application Ser. No. 08/478,839 (allowed; issuing on Nov. 4, 1997) discloses an apparatus and corresponding methods for converting a spherical data set into a single image which contains all visual information. An exemplary application of this apparatus is a heads up display for an aircraft which allows the pilot to view his/her environment from a single viewpoint. This permits the pilot to view sections of the airspace which would normally be obscured by the aircraft. It should be mentioned that Ser. No. 08/478,839, which was invented by the present inventor, is incorporated herein by reference for all purposes. It will be appreciated from the above-identified application that the spherical data set can be developed from a series of planar images, e.g., six images defining a cube. It will be appreciated that the spherical data set generated for use in Apple QuickTime VR image display makes use of multiple images which, while not orthogonal to each other, still require multiple stitching steps to construct the spherical data set. It is desirable to reduce the number of image input devices, since this will decrease the number of images which must be stitched together to form a spherical data set.
It should be mentioned that the problem with generating the spherical data set is exacerbated by the fact that the camera must occupy a fixed point in space and all images are developed by rotating the camera about that fixed point. For example, IPIX Corporation provides displayable spherical images called IPIX. An IPIX is an interactive, spherical image, offering users a complete field of view, from earth to sky, floor to ceiling, horizon to horizon. An IPIX is created from two opposing photographs captured by a fisheye lens. It will be appreciated that the IPIX can only be generated with respect to a single point in space. While this is generally acceptable for advertising and virtual museums, the above mentioned spherical data sets cannot be generated from the middle of, for example, a football field.
What is needed is an apparatus for generating spherical data sets which allows a significant displacement between the camera and the spatial center of the spherical data set, thereby improving the versatility with which spherical data set can be generated. It would be highly desirable in the apparatus where robust. Preferably, the apparatus could be readily repositioned.